焊接厂房烟尘治理及其节能环保应用

焊接生产过程中会因为焊接材料与母材的结合产生大量焊接烟尘和气体,其对操作人员的身体健康会造成恶劣影响,并引发各类呼吸及尘肺疾病,做好烟尘治理工作不仅是保证焊接工人健康的重要途径,也是提高焊接生产质量的关键。在烟尘治理中,采用节能环保手段也引起了当前众多研究人员的关注,有必要积极做好烟尘治理工作,以便维护工作人员的健康,提高企业的焊接生产质量。基于此,本文就焊接厂房与烟尘治理及其节能环保应用进行了分析。     

百万燃煤机组降低飞灰含碳量的实验及分析

飞灰含碳量是衡量锅炉燃烧效率的一项重要指标,若能在正常运行中降低飞灰含碳量,则能大大提升锅炉效率并降低发电成本。本文主要介绍了对一台1000MW机组进行配煤掺烧、配风方式的改变调整实验,来验证不同配煤、配风方式组合和确定的煤粉细度下对飞灰含碳量的影响,从实验结果中得出一种较好的配煤掺烧、配风方式、煤粉细度的搭配,可将飞灰含碳量降低到4%以下,并将其应用到生产实际中。     

烟尘浓度自动检测仪的研制

烟尘浓度检测是环境监测的一项重要内容。本文介绍一种以８０３１单片机为核心，采用光散射法测定烟尘浓度的自动检测系统，为高浓度烟尘及其它粉尘的测量提供一种有效的检测手段。本系统可作为环保部门的执法工具。     

焦炉装煤烟尘治理方法评介

本文介绍了国内外焦炉装煤烟尘治理的各种方法及特点，为今后焦炉装煤烟尘治理提供了参考依据。     

汽车车身制造中焊装车间烟尘解决方案

在汽车白车身制造过程中,白车身焊接会产生大量的烟尘,为优化操作工工作环境,降低操作工身体危害,减少污染气体排放,焊接烟尘治理成为一个重要的课题。本文主要介绍除尘设备的基本构造、焊装车间烟尘解决方案,并结合成功应用案例,详细的阐述了焊接烟尘的治理方案,为后期除尘方案的合理制定提供借鉴意义。     

用抽条式燃煤炉排改造烘炉

抽条式炉排是一种新型结构炉排，其特点是燃烧面积大、煤层薄、进煤速度慢、煤燃烧充分、炉温均匀，排出烟尘很少，达到了国家规定的烟尘排放标准。     

AZD20-2.5/400-AⅡ型锅炉改进

分析了某电厂AZD20-2.5/400-AⅡ型锅炉烟尘排放浓度超出锅炉大气污染物排放标准的极限值,就此原因提出了改进方案,将风力机械抛煤倒转链条炉排改成常规正转分层给煤链条炉排,增加炉拱改善燃烧条件,经改进后的锅炉提高了燃烧效率、降低了烟尘排放浓度,取得了预期效果。     

碳钢焊接烟尘治理技术探讨

1、概述 在工业化生产发展的同时会带来一些环境污染,本文着重简述碳钢焊接过程中产生大量烟尘造成的危害,怎样选择适合的碳钢焊接烟尘治理方法,特别是在焊接工位集中、机器人自动焊接产烟量大、手工连续焊接时间长、上有行车吊装或悬臂吊工作的现场,如何设置烟尘捕捉是烟尘治理的关键。     

锅炉的强化燃烧技术

锅炉的强化燃烧技术北京建筑工程学院高丽云，陈钰据有关资料统计，１９９３年世界银行贷款给我国为２７０亿美元，其中用于能源和治理环境污染达４０％左右。我国的锅炉房是重点能耗设备，也是重要的污染源之一。锅炉的煤耗量占我国煤产量的一半到三分之一。每年烟尘排放...     

焊接烟尘的净化技术及设备的最新研发动态和发展趋势

分析了焊接烟尘对人体的危害，列举了不同工况下的焊接烟尘净化技术，特别是分层送风技术在整体厂房焊接烟尘治理工程中的应用。SINBRAN烧结板过滤元件的性能特点，新型除尘器的研发推广。     

High resistivity characteristics of the sinter dust generated from the steel plant

The electrical resistivity of sinter dusts generated from the steel industry and coal fly ash from the coal power plant has been investigated using the high voltage conductivity cell based on JIS B 9915 as a function of temperature and water content. Dust characterization such as the chemical composition, size distribution, atomic concentration, and surface structure has been conducted. Major constituents of sinter dusts were Fe₂O₃ (40–74.5%), CaO (6.4–8.2%), SiO₂ (4.1–6.0%), and unburned carbon (7.0–14.7%), while the coal fly ash consisted of mainly SiO₂ (51.4%), AI₂O₃ (24.1%), and Fe₂O₃ (10.5%). Size distributions of the sinter dusts were bi-modal in shape and the mass median diameters (MMD) were in the range of 24.7–137μm, whereas the coal fly ash also displayed bi-modal distribution and the MMD of the coal fly ash was 35.71 μm. Factors affecting resistivity of dusts were chemical composition, moisture content, particle size, gas temperature, and surface structure of dust. The resistivity of sinter dusts was so high as 10¹⁵ ohm cm at 150 °C that sinter dust would not precipitate well. The resistivity of the coal fly ash was measured 1012 ohm cm at about 150 °C. Increased water contents of the ambient air lowered the dust resistivity because current conduction was more activated for absorption of water vapor on the surface layer of the dust.     

Application of scanning electron microscopy for pollution particle source determination in residential dust and soil

Many tons of electric furnace flue dust accumulated in an industrial area in Tifton, Georgia. Vehicles transporting the flue dust, classified as K061 hazardous waste because it contained lead and cadmium, initially dumped the material in a warehouse. Once the warehouse was full, the flue dust was dumped in uncovered piles. Run-off from the piles and wind-driven particles had the opportunity to contaminate nearby industries, residential buildings, and neighborhood soils over a period of many years. Scanning electron microscopy-energy dispersive x-ray spectrometry (SEM-EDS) was used to compare the morphology and chemical composition of fly ash dust from the suspect pile with samples collected from the surrounding buildings and soil. Adhesive samplers were used to collect dust that had accumulated in buildings surrounding the fly ash dump site. Suspect dust particles were analyzed by SEM-EDS and compared with known dust particles from the fly ash pile. Soil samples were dried, sieved, and the “fines” analyzed by SEM-EDS for comparison with samples from the fly ash pile. Fly ash particles similar in morphology and chemical composition to the fly ash in the suspect pile were identified in most of the buildings sampled surrounding the fly ash dump site and in all of the soil samples analyzed surrounding the dumpsite. This case study illustrates the usefulness of applying morphology and chemistry information acquired by SEM-EDS for pollution particle source determination.     

粉煤灰超细磨的开发与应用

资源综合利用是我国经济建设中的一项重大技术经济政策,粉煤灰是可利用资源,国家积极支持和鼓励粉煤灰的综合利用,先后制定了一系列的政策和标准。在目前国家环保要求不断提高,灰场占地日益紧张的客观条件下,对分选后粗灰进行磨细,使其达到符合国家标准的Ⅰ级、Ⅱ级灰,提高其附加值,从而实现粉煤灰零排放的已成为势在必行的趋势。论述了磨细后粉煤灰的利用价值及粉煤灰超细磨系统的设计。     

粉煤灰和氧化钙烧结过程的热力学分析

粉煤灰是煤在锅炉中燃烧时产生的一种细颗粒物质。粉煤灰中含Al2O315%~35%,含SiO250%左右。随着Al2O3工业的迅猛发展,铝土矿资源日渐耗尽,如果把粉煤灰作为一种生产Al2O3的后备资源,不仅利于Al2O3工业的持续发展,而且对提高粉煤灰的综合利用价值具有重要意义。本文通过分析粉煤灰与CaO烧结过程的热力学数据,得到最佳反应温度,为从粉煤灰中提取Al2O3奠定了理论基础。     

Study on the Preparation and Tribological Properties of Fly Ash as Lubricant Additive for Steel/Steel Pair

Fly ash, generated during the combustion of coal for energy production, has been regarded as an environmental pollutant if not properly disposed of. Many aggressive efforts have been evaluated to recycle the fly ash. In this paper, a new approach was developed to prepare lubricant additive based on fly ash and the tribological properties were investigated in detail. The results show that fly ash modified with oleic acid not only performs favorable dispersive ability, but also significantly improves the friction-reducing and anti-wear abilities for steel/steel contact. Based on the characterization of the wear scars by scanning electron microscopy, Raman spectroscopy and energy-dispersive X-ray spectroscopy, the excellent tribological properties are attributed to the synergies of fly ash and oleic acid because fly ash can act as spacer and bearing and deposit on the worn surfaces to significantly improve the friction-reducing and anti-wear abilities, and the introduction of strong polar groups can make fly ash easily form a stable and successive tribofilm on the rubbing surfaces throughout the sliding process.     

Effect of ash fraction and particle size on ash deposition during pulverized coal combustion

Coal is an important energy source to increase consumption continuously. However, the ash residues from coal combustion have produced ash deposition that causes slagging and fouling in boilers. The goal of this study is to examine the characteristics of ash deposits (i.e., the effects of the ash fraction and particle size) in pulverized coal combustion. For this study, five coals (Suek, Macqurie, Berau, Lanna and Vitol) are used, which have similar chemical components in the ash but differences in the ash fraction. A Thermomechanical analysis technique (TMA) and Drop tube furnace (DTF) are used to analyze the tendencies in the ash fusibility and deposition with temperature, respectively. Moreover, the size and morphology of the fly ash are analyzed for physical changes by using a particle-sizedistribution analyzer and Scanning electron microscopy (SEM), respectively. In the TMA results, all coal types have a similar fusibility because of the similar chemical components in the ash. The order of the deposited mass is Suek, Macqurie, Berau, Vitol and Lanna in accordance with the ash fraction in the DTF. The ash fraction in coal is a major factor in the ash deposit according to these results. The size of the fly ash changed compared to that of the raw coal according to the results of a particle-size analysis and SEM owing to physical processes such as fragmentation, shedding and coalescence during coal burning. On this basis, a deposition model is developed with the ash fraction and particle size. The model results are in good agreement with the measurements. The results demonstrate that the particle size and ash fraction influence the deposit.

     

改性粉煤灰结构与吸附性能及其在废水处理中的应用研究

采用碳酸钙、碳酸钠、硫酸及碳酸钠处理后再加硫酸等改性剂对粉煤灰进行改性处理;通过X-射线衍射分析研究其改性后的物相结构,并对几种废水进行吸附试验.研究探索出了粉煤灰及其改性后的吸附机理.并将其应用到了废水处理中,收到了较好的效果.     

Characterization of ultrafine coal fly ash particles by energy-filtered TEM

In this study, energy-filtered transmission electron microscopy is demonstrated to be a valuable tool for characterizing ultrafine coal fly ash particles, especially those particles encapsulated in or associated with carbon. By examining a series of elemental maps (K-edge maps of C and O, and L-edge maps of Si, Al, Ti and Fe) recorded using the three-window method, considerable numbers of titanium and iron species with sizes from several nanometres to submicrometre were shown to be present, typically as oxides dispersed in the carbonaceous matrix. Crystalline phases, such as rutile and iron-rich oxide spinel, were also identified from electron diffraction patterns and high-resolution TEM images. Information about these ultrafine coal fly ash particles regarding their size, morphology, elemental composition and distribution, and crystalline phases, which has not been available previously in conventional ash studies, should be useful in toxicological studies and related environmental fields.     

北京冬季大气颗粒物中铅的同位素丰度比的测定和来源研究

本文报道了北京市冬季（1998-1999年）大气颗粒物样品的无机多元素和铅同位素丰度比的测定数据。分别采用HR-ICP-MS和TOF-ICP-MS测定铅同位素丰度比,结果表明ICP-MS的测定精度可适用于大气中铅的来源研究。大气颗粒物样品中一些特征无机元素含量,如Br、Ti、Pb、Zn,与铅的同位素丰度比之间存在相关性。在铅含量高的样品中机动车尾气排放的贡献明显,在铅含量低的样品中土壤扬尘和燃煤飞灰的贡献增加;其中部分样品表现出来自西伯利来地区的长距离传输的特征。样品聚类分组结果结合气象信息可以得到合理解释。应用铅的同位素技术来研究北京市大气颗粒物中的铅的来源是可行的。     

改善大掺量粉煤灰水泥石抗碳化性能的试验

采取高温养护、粉煤灰磨细和水泥石内部补足碱3种方法,对大掺量粉煤灰水泥石的抗碳化性能进行改善,利用碳酸盐定量分析法对改善后水泥石的抗碳化性能进行测试,结果表明：高温养护和粉煤灰的磨细对大掺量粉煤灰水泥石的抗碳化性能有较好的改善效果;补足碱对大掺量粉煤灰水泥石抗碳化性能的改善作用不大。